PyQT5 标签的鼠标悬停事件

Question

I am a newbie to python i want that if i move my mouse over the label with text stop on it then it should change the value of a variable Stop to True so that i may pause/Stop ,my program. i have looked the code at Mouseover event filter for a PyQT Label and tried to run it but nothing is being shown up Please guide me... the code is as under

from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
from PyQt5.QtCore import *
from PyQt5 import *
import sys
class mouseoverEvent(QtCore.QObject):
    def __init__(self, parent):
        super(mouseoverEvent, self).__init__(parent)
        self.initUI()
    def eventFilter(self, object, event):
        if event.type() == QtCore.QEvent.MouseMove:
            print( "mousemove!")
            return True
        else:
            return False

    def initUI(self):
        self.filter = mouseoverEvent(self)
        self.label.installEventFilter(self.filter)
        self.lbl=QLabel(self)
        self.lbl.setText(self,"hellojjj")
        self.setGeometry(1000, 30, 300, 100)
        self.setWindowTitle('QLineEdit')

        self.show()

'''if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = mouseoverEvent()
    sys.exit(app.exec_())'''''

I Shall be greatly thankful...

Answer 1

1. If you've already imported

   from PyQt5.QtWidgets import * from PyQt5.QtGui import * from PyQt5.QtCore import *

   there is no need to

   from PyQt5 import *

2. Once you've imported QtCore, you no longer need to call its functions/classes with 'QtCore.QEvent', Just using QEvent is fine

3. I believe the question you linked to used PyQt4. In PyQt5, the initialization procedure for the class changed

The code below should work.

from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
from PyQt5.QtCore import *
import sys

class mouseoverEvent(QWidget):

    def __init__(self):
        super().__init__()
        self.stop = False # your 'stop' variable
        self.initUI()

    def initUI(self):
        self.lbl=QLabel(self)
        self.lbl.setText("Hover over me to stop the program")
        self.lbl.installEventFilter(self)
        self.setGeometry(1000, 30, 300, 100)
        self.setWindowTitle('QLineEdit')

        self.show()

    def eventFilter(self, object, event):
        if event.type() == QEvent.Enter:
            print("Mouse is over the label")
            self.stop = True
            print('program stop is', self.stop)
            return True
        elif event.type() == QEvent.Leave:
            print("Mouse is not over the label")
            self.stop = False
            print('program stop is', self.stop)
        return False


if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = mouseoverEvent()
    sys.exit(app.exec_())

if you only want the stop to activate over a label with certain text change your eventFilter function to:

def eventFilter(self, object, event):
    if hasattr(object, 'text'): #check to see if the object has text, otherwise if you hover over something without text, PyQt will return an error
        if object.text() == "Hover over me to stop the program":
            if event.type() == QEvent.Enter:
                print("Mouse is over the label")
                self.stop = True
                print('program stop is', self.stop)
                return True
            elif event.type() == QEvent.Leave:
                print("Mouse is not over the label")
                self.stop = False
                print('program stop is', self.stop)
    return False

Answer 2

Please find the reference:

from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
from PyQt5.QtCore import *


class Label(QLabel):
    def __init__(self, *args, **kwargs):
        QLabel.__init__(self, *args, **kwargs)

    def enterEvent(self, event):
        print("hovered")

    def leaveEvent(self, event):
        print("left")

Answer 3

Remember that Python is very flexible, so there is no need to subclass QLabel .

For example:

def enter(event):
    print("Enter")

def leave(label):
    print("Leave")

label = QLabel("Hello")
label.leaveEvent = leave
label.enterEvent = enter

Or you can use lambdas:

label = QLabel("Hello")
label.leaveEvent = lambda e: print("Leave")
label.enterEvent = lambda e: print("Enter")